Brain-Computer Interface Training Fosters Perceptual Skills to Detect Errors

Accurate perception of subtle visuo-motor errors is essential for perceptual and sensorimotor learning, and supports timely corrective actions in precision-based task. However, conventional perceptual training, typically based on response-accuracy feedback, is limited in improving sensitivity to small, subtle errors. While prior approaches have focused on modulating sensory regions to enhance perceptual learning, we propose an alternative approach that targets a cognitive neural marker: the error positivity (Pe), a component of the error-related potential (ErrP) originating in the anterior cingulate cortex, a key decision-making region. We hypothesize that the Pe, which reflects conscious awareness of errors, serves as a modifiable neural correlate of error perception. In a five-day longitudinal study, we show that providing real-time feedback on the presence or absence of ErrPs during perceptual training accelerates perceptual learning at $3^{\circ }$ errors and enhances perceptual performance at $6^{\circ }$ errors without accelerating the learning rate, relative to behavioral training alone. These behavioral gains were accompanied by increase in Pe amplitude. Together, these findings offer new neurophysiological insights into the mechanisms of error perception, and establish ErrP-based brain-computer interface interventions as a promising approach for fostering perceptual learning in domains where detecting subtle errors is critical.